229 Mountbatten Road, #01-23 Mountbatten Square, Singapore 398007
hycommon@hy-me.com.sg
+65-63386455
229 Mountbatten Road, #01-23 Mountbatten Square, Singapore 398007
+65-63386455
Contact

Arc Flash Analysis

An Electrical Arc occurs when electric current passes through the air because the air can’t handle the building voltage.

Arc flash is when a lot of energy is suddenly released because of an electric arc in electrical equipment. This release of energy includes heat, light, sound, and blast waves. Arc flash can get extremely hot, reaching temperatures as high as 19,000 °C. This intense heat can turn materials like copper, steel, or aluminum into vapor.

Factors that may result in an Arc Flash:

  1. Human errors such as tools dropping into energized switchboard during maintenance
  2. Aging or insulation defects of electrical components
  3. Ingress of dust/vermin into electrical equipment compromising the distance between energized parts
  4. Personnel not adhering to safety procedures during maintenance or operations
  5. Overheating of contacts due to loose connections or corrosion
  6. Electrical components subjected to harsh, highly humid or corrosive environments
  7. Inadequate protection by relay systems
  8. Ferroresonance generated in instrument transformers
  9. Closing of breakers to an existing fault
  10. Inadequate insulation at cable terminations

 

Arc Flash Incidents (AFIs) occur from electrical sources and electric potential devices producing electric currents that travel through the air or other mediums as opposed to travelling through its intended path. As electric arcs or flash-overs happen, they produce large amounts of energy with extreme heat. These fire-like flashes happen very quickly in under a second or can sometimes continue for longer periods, even reaching minutes in duration. Arc flash events (AFEs) are extremely dangerous. Wikipedia defines arc flash (AF) as “a type of electrical explosion or discharge that results from a low-impedance connection through air to ground or another voltage phase in an electrical system. It’s also “the light and heat produced from an electric arc supplied with sufficient electrical energy to substantially damage, harm, cause fire, injure,” including death.

An arc can occur during electrical shorts, faults, and voltage spikes, capable of producing flash-overs between two or more electrodes through an air gap or other medium.

Electrical arcs can be caused by malfunctions of protective equipment, deteriorated or defective insulation, human contact, or contact with other conducting materials. Breaks, cracks, or corrosion in insulation and electrical connections can cause AFIs. AFs can also be caused by breaching the minimum safe zone of an electric energy source or an electric potential device (PD).

AFEs can create deadly and harmful consequences to humans and their surroundings with excessive temperatures reaching over 35,000 degrees Fahrenheit at the arc terminals, which is surprisingly hotter than the surface temperature of the sun. This extreme heat can ignite equipment and combustible materials that are nearby, including melting steel and other metals within a second or less. Even worse, it can severely burn human skin and tissue while igniting all types of combustible clothing. AFs produce large amounts of energy that discharge flashes of bright light, like lightning, causing momentary or permanent blindness.

Arc blasts can create high-pressure forces and electrical explosions sending debris and equipment through the air like dangerous missiles. Arc blasts can also produce enough pressure to burst human eardrums.

AFs can occur from both alternating current (AC) and direct current (DC) electrical circuits.